1、AECMA Technical Report Rapport Technique AECMA AECMA Fach beric ht Edition approved for publication Extra copies can be supplied by B.N.A.E. Technopolis 54 - 199, rue Jean-Jacques Rousseau 2000-02-29 92138 ISSY - LES - MOULINEAUX CEDEX - FRANCE 0 aecrna 201 TR 4271 Edition I 02-00 _ _ PUBLISHED BY T
2、HE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Guliedelle 94 - 8-1200 BRUXELLES - Tel. (+32) 2 775 81 10 - Fax. (+32) 2 775 81 11 ICs: 49.080 Descriptors: Hydraulic fluid power, fluid circuits, hydraulic component, sealing joint, O-ring, dimension, designation ENGLISH VERSION Aerospace seri
3、es O-rings grooves Design criteria for O-ring grooves Basic calculations Srie arospatiale Gorges pour joints toriques Critres de conception Calculs de base Luft- und Raumfahrt Nuten fr O-Ringe Konstru ktionsrnerkmale Grundlegende Berechnungen This Technical Report was drawn up by the Technical Commi
4、ttee C 8 of the AECMA Standardization Committee. The reason which led to the publication of the documenf as a Technical Report is explained in the foreword. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction
5、 or networking permitted without license from IHS-,-,-Foreword The main task of AECMA Technical Committees is to prepare EN standards. In exceptional circumstances, however, the publication of a Technical Report of one of the following types may be proposed: - type 1, the subject is still under tech
6、nical development requiring wider exposure; - type 2, a Technical Committee has collected data of a different kind from that which is normally published as a European Standard. Technical Committee C 8, Engines, decided to publish this document in the form of a Technical Report of type 2, because con
7、tained information consists of values for guidance and must in no way be considered as a technical requirement. Design solution of a O-ring remains the sole responsibility of the designer, Contents O 1 2 3 4 4.1 4.2 5 5.1 5.1.1 5.1.2 5.2 5.2. I 5.2.2 6 6.1 6.2 6.3 6.4 6.5 6.6 6.6.1 6.6.2 6.7 6.7.1 6
8、.7.2 7 7.1 7.2 7.3 7.4 8 8.1 8.1.2 8.2 8.3 8.4 8.5 8.1.1 8.1.3 Introduction . . . . . . . . , , . . . . . , . . . . . , , . , , . . . . . . . . . . . , , , . . . . , . . . . . . . . . . , . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . , , . , . , . , . , . ,
9、. . . . . , . . . , . . , . . . . , , . , , . , . . . . , . . . . , . . . . . , . . , , , , . . , , . . . . . , . , . . , , . , . . . . . . . . . . . . . . . . . . . . . . . , , , , Symbols . Generals Rubber families concerned . Permissible pressures Radial sealing Rod housings Bore housings . Axial
10、 sealing Face seals for internal pressure source Face seals for external pressure source . Factors influencing the quality of sealing. ._It.5MPa 6.1 Surface roughness Surface roughness value and character of the component in contact with the O-ring are dependent on the application and its life requi
11、rements, and where doubt exists should be subject to agreement between manufacturer and user. See table 1. with pressure variation s5MPa I 5MPa Table 1 Dimensions in micrometres continuous pressure Surface with pressure variation Groove d2 2 min. Side surfaces Inside diameter 1,80 2,65 3,55 5,30 7,O
12、O 1,1 1,5 188 2,7 3,6 Homologous surface Roughness s 5 MPa 12,5 5MPa r5MPa 5MPa i-+ 6.2 Corner and edge radii See table 2. Table 2 Dimensions in millimetres 6.3 I 613 6,3 l+l 0,2 to 0,4 0,l to 0,3 0,4 to 0,8 0,8 to 1,2 Lead-in chamfers Use a chamfer angle of 15“ to 20“ to prevent damage to the O-rin
13、g on assembly. Provide for the length of lead-in chamfer Z as shown in table 3. It is imperative that chamfer edges be rounded. 6.4 Groove run-out tolerances - Groove diameter d3 or ds I 50; maximum run-out tolerance Y = 0,025 - Groove diameter d3 or 6 50; maximum run-out tolerance Y = 0,05 Copyrigh
14、t Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA TR Li271i-ENGL 2C100 II 10123LL 0017920 590 Page 9 TR 4271 1 02-00 Bore diameter, rod mounted d4 O-ri
15、ng groove diameter, rod mounted d3 d4 Total tolerances + d3 6.5 Housing diameter tolerances The following tolerances as shown in table 4 are recommended. 1,80 2,65 335 5,30 7,OO + 0,06 + 0,07 + 0,08 + 0,09 +O,ll O O O O O O O O O O - 0,04 - 0,05 - 0,06 - 0,07 - 0,09 0,l o 0,12 0.14 0,16 0,20 Table 4
16、 Dimensions in millimetres Rod outside diameter, bore mounted O-ring groove diameter, bore mounted Total tolerances Housing diameter I d2 O O O O O - 0,04 - 0,055 - 0,06 - 0,07 - 0,09 + 0,06 + 0,07 + 0,08 + 0,09 + 0,ll O O O O O d5 d6 d5 + 0,lO 0,12 0,14 0,16 0,20 d6 Bore diameter, bore mounted O-ri
17、ng groove outside diameter, internal pressure I dg I Rod outside diameter, rod mounted dl o H8 HI 1 4 t7 O-ring groove outside diameter, external pressure I I hl 1 Important: in the event of high pressure together with pulsatory phenomena, it is imperative that the clearance between the rod and bore
18、 be reduced. A H7 tolerance for bore and g6 for rod are recommended. This recommendation is all the more valid in that the seal section is small and the seal diameter is large. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for R
19、esaleNo reproduction or networking permitted without license from IHS-,-,- STD*AECMA TR 4271-ENGL 2000 E Lc1223LL 0017921 427 = Page 10 TR 4271 : 02-00 Application Static radial Static axial 6.6 Housing width and depth 6.6.1 Housing width (b) + 0,25 See table 5, with tolerance o d2 i ,80 2,65 3,55 5
20、,30 7,oa 2,40 3,60 4,80 7,10 9,20 2,60 3,80 5,OO 7,30 9,40 d2 6.6.2 See table 6. Housing depth (h or t) Radial sealing Axial sealing Bore housing I Rod housing Table 6 Dimensions in millimetres t f h a This value is to be used to calculate the housing diameter d3 or de. The minimum and maximum value
21、s were used to establish the O-ring squeeze values as specified in table IO. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA TR LUL-ENGL won
22、m I,OLZI,I, OOI, 33 m Page 11 TR 4271 02-00 O-ring inside diameter di mm 55 6.7 Stretch and compression O-ring 6.7.1 Radial sealing 6.7.1 .I Stretch See table 7. Stretch Yin % rnax. min. a a Table 7 O-ring inside diameter di mrn 55 5 and I 10 10 and 5 and I 10 I 8 l 400 IO and 400 I _ a The stretch
23、values are to be individually calculated for each d1 as the clearance between dl max. and di min. is important taking into account the O-ring casting tolerances. It is advised to be as as near as possible to the values applying to the diameter range of di z 5 and 5 10 while imperatively keeping a 2
24、Oh minimum stretch. 6.7.1.2 Compression See table 8. Table 8 Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA TR 4273-ENGL 2000 1022311 003772
25、3 2TT I Page 12 O-ring inside diameter dl a mm I100 TR-427 I : 02-00 Internal pressure External pressure Max. K % compression on d7 Max. Y YO stretch on ds 4 6.7.2 Axial sealing See table 9. Table 9 200 2 3 I Yo or a maximum of 0,8 mm 100 and I 200 a in this table but less than 5 %. For the 1 I 5 mm
26、 diameters, the stretch values (external pressure) may be greater than the values 7 Method of calculating housing dimensions 7.1 d3 rnax. = d4 min. - 2 t nom. Tolerances as per table 4 Depth t nom. as table 6 Width b as table 5 Radial application - Piston housing 7.2 ds min. = d5 max. + 2 t nom. Tol
27、erances as per table 4 Depth f nom. as table 6 Width b as table 5 Radial application - Rod housing 7.3 d7 nom. = di nom. + 2 d2 nom. Tolerances as per table 4 Axial application - Internal pressure 7.4 d8 nom. = dl nom. Tolerances as per table 4 Axial application - External pressure 8 Design criteria
28、 Housing dimensions are derived from consideration of such design criteria as: - O-ring stretch or compression; - cross-section reduction; - O-ring squeeze; - O-ring swell. This clause amplifies these criteria and indicates the extreme values within which they are applied. Copyright Association Euro
29、peene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 13 TR 4271 02-00 8.1 O-ring stretch or compression 8.1 .I Rod housing Only stretch of an O-ring inside diameter dl has been
30、permitted. A clearance between d3 and di is not permitted, a minimum stretch is required (see table 7). Thus smallest permitted d3 = di max. (1 + Y1100 min.) largest permitted d, - d, min. dl min. max. Y % = x 100 Or largest permitted d3 = di min. (1 + Y1100 max.) Thus smallest permitted d3 = dl max
31、. (1 + Y1100 min.) Largest permitted d3 = dl min. (1 + Y11 O0 max.) d4 max. at the upper limit or range d4 min. = d3 max. + 2 t min. with d3 max. = dl min. (I + Y/lOO max.) and t min. as table 6 I I d4 min. = di min. (1 + Y1100 max.) + 2 t min. 1 d4 table = d4 min. + tolerance (see table 4) (1) 1 d4
32、 min. at the lower limit or range d4 max. = d3 min. + 2 t max. with d3 min. = d, max. (1 + Y/lOO min.) and t max. as table 6 d4 max. = dl max. (1 + Y/lOO min.) + 2 t max. d4 tabulated = 4 max. -tolerance (see table 4) (2) Since nominal size in the case of cylinder diameters (d4) is the minimum, rang
33、e of nominal cylinders over which any seal may be used is from formula (1) to formula (2). The bore diameter (diameter d4) for which the O-ring could be used will be ranged between the formula (I) results and those of the formula (2). Copyright Association Europeene des Constructeurs de Materiel Aer
34、ospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TR-4271: 02-00 EXAMPLE 1: Suppose that there is an O-ring of code A0400, used as an O-ring of piston type dl max. = 40,33 mm d, min. = 39,67 mm d2 max. = 1,88 mm d2 min
35、. = 1,72 mm 2tmax. = 2,92 mm 2 tmin. = 2,72 mm Y% max. = 6 Y% min. = 2 d4 min. = d3 max. + 2 t min. d3 max. = 39,67 (I + 0,06) = 42,05 d4 min. = 42,05 + 2,72 = 44,77 d4 table = d4 min. + tolerance (table 4) = 44,77 + o = 44,77 d4 max. = d3 min. + 2 t max. d3 min. = 40,33 (1 + 0,02) =41,137 d4 max. =
36、 41,137 + 2,92 = 44,057 d4 table = d4 max. - tolerance (table 4) = 44,057 - 0,06 = 43,997 Range of use of diameter d4 nominal values by the O-ring of code A0400 I d4 nom. = 43,997 to 44,77 I The choice of a d4 nominal in the above given range implies to redefine d3 in accordance with the equation: d
37、3 nom. = d4 nom. - 2 t nom. The tolerance of d3 is given in table 4. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8.1.2 Bore housing Only compressio
38、n of an O-ring outside diameter Dl (d1 + 2 d2) has been permitted. A clearance between d6 and Dl is not permitted, a minimum compression (K %) is required (see table 8). Thus largest permitted d6 = (dl min. + 2 d2 min.) (1 - WIOO min.) Maximum compression = K Oh (specified in table 8) d, max. + 2 d,
39、 max. - smallest permitted de d, max. + 2 d, max. max. K YO = x 100 Or smallest permitted de = (dl max. + 2 d2 max.) (1 - KI100 max.) Largest permitted d6 = (dr min. + 2 d2 min.) (I - Ki100 min.) Smallest permitted de = (d, rnax. + 2 d2 max. (1 - W100 max.) 5 max. at the upper limit or range d5 min.
40、 = d6 max. - 2 t max. with d6 max. = (d, min. + 2 d2 min.) (1 - KI100 min.) and t max. as table 6 d5 min. = (dl min. + 2 d2 min.) (I - NI00 min.) - 2 f max. d5 tabulated = d5 min. + tolerance (see table 4) (3) 5 min. at the lower limit or range d5 max. = d6 min. - 2 t min. with d6 min. = (d, max. +
41、2 d2 max.) (1 - WIOO max.) and f min. as table 6 d5 max. = (d, max. + 2 d2 max.) (1 - N100 max.) - 2 t min. d5 tabulated = d5 max. - tolerance (see table 4). (4) .e. range of rod diameters (s) over which any O-ring may be used is given by formula (3) to formula (4). These are nominal sizes. Copyrigh
42、t Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA TR 4271-ENGL 2000 LOI2333 0037927 745 W Page 16 TR-4271: 02-00 EXAMPLE 2: Suppose that there is an O-
43、ring of code A0400, used as an O-ring of rod type dl max. = 40,33 mm dl min. = 39,67 mm d2 max. = 1,88 mm d2 min. = 1,72 mm 2tmax. = 3,02 mm 2 tmin. = 2,82 mm Y%max. = 6 Y % min. = 2 d5 min. = d6 max. - 2 t max. d6 max. = (39,67 + (2 x I ,72) (1 - 0,02) = 42,248 d5 min. = 42,248 - 3,02 = 39,228 d5 t
44、able = 39,228 + 0,04 = 39,268 = ds min. + tolerance = (table 4) d5 max. = d6 min. - 2 t min. d6 min. = (40,33 + (2 x 1,88) (1 - 0,06) = 41,445 d5 max. = 41,445 - 2,82 = 38,625 d5 table = d5 max. - tolerance (table 4) = 38,625 + O = 38,625 Range of use of diameter d5 nominal values by the O-ring of c
45、ode A0400 ds nom. = 38,625 to 39,268 The choice of d5 nominal in the above given range implies to redefine de in accordance with the equation: d6 nom. = ds nom. + 2 t nom. The tolerance of d6 is given in table 4. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by I
46、HS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 17 STD-AECMA TR q271-ENGL 2000 m LO12311 0037928 881 m TR 4271 02-00 8.1.3 Axial housing 8.1.3.1 Internal pressure The K % compression of the O-ring outer nominal diameter (see table 9)
47、. d7 max. at the upper range or limit d7 max. = dl nom. + 2 d2 nom. + tot. HI1 d, tabulated = d7 max. - tol. HI1 d7 tabulated = d, nom. + 2 d2 nom. The maximum compression K % shall be associated with the nominal diameter plus the tolerance on this diameter. d7 min. at the lower range or limit d7 mi
48、n. = d7 max. (1 - KlIOO) establishes the absolute d7 minimum diameter d7 tabulated = d7 min. 8.1.3.2 External pressure The Y % stretch of the O-ring inside nominal diameter (see table 9). da max. at the upper range or limit da max. = dl nom. (1 + Y/lOO) = da tabulated de min. at the lower range or l
49、imit da min. = dl nom. da tabulated = d, nom. + tol. hl 1 8.2 Cross-section reduction Where O-rings are stretched, there is a reduction in cross-section. This can be calculated as follows: d, max. - d, min. 10 d, min. Maximum reduction This formula exaggerates the reduction in cross-section slightly for any stretch below 1
